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Tuesday, July 24, 2012

GMO Myths and Truths: The genetic engineering technique (1.1)

So here we are. The first section of GMO Myths and Truths. This will probably be the shortest section review as this one has no cited papers backing it up. That isn't immediately a negative to it as it seems to be arguing definitions. As the section header states...

Myth: Genetic engineering is just an extension of natural breeding Truth: Genetic engineering is different from natural breeding and poses special risks

Depending on how you are defining "just an extension" that could be true or false. It is true that once the trans-gene is inserted, we still have the organism develop by natural processes. The trans-gene is still DNA just like the rest of the DNA in the modified organism. It will still be read like every other gene by the same mechanisms in the cell, and produce proteins and amino acids just like any other gene would. The gene may effect the expression of other genes, it may produce novel proteins, but this is all standard cellular mechanics. The same could happen in my cells if there was a insertion or frameshift mutation in one of my own genes. Now what I've just said there seems to be part of the argument, as it reads closely to the first paragraph of the paper.

GM proponents claim that genetic engineering is just an extension of natural plant breeding. They say that GM crops are no different from naturally bred crops, apart from the inserted foreign GM gene (transgene) and its protein product. But this is misleading. GM is completely different from natural breeding and poses different risks.

Well of course GM is different from natural breeding. In a typical natural gamete fusion, genes only come from genetically compatible organisms. Also, there typically aren’t laboratories or genetic screenings going on in that process, though IVF in humans can introduce that. However, even if we are allowing technological assistance to "natural breeding" it still doesn't involve adding genes from organisms off on a far branch of the evolutionary tree. This is also pretty well stated in the paper, but with one part that is a little off.

Natural breeding can only take place between closely related forms of life... In this way, the genes that carry information for all parts of the organism are passed down the generations in an orderly way.

Natural breeding is a relatively orderly process when compared with a system without a method for lowering its own entropy at the cost of local entropy increase in other locations (what we lay people call metabolism), but it is hardly without errors and mistakes. If it weren't for mutations, the less than orderly passing along of information between generations, there would be no evolution. No evolution, no humans banging away on keyboards arguing about inserting genes from an antarctic fish into tomatoes to give them a frost resistant protein.

After the next paragraph we are introduced to a simplified step-by-step version of the genetic modification process. Lets take a look at each step.

The Genetic Modification Process, abridged

1. In a process known as tissue culture or cell culture, tissue from the plant that is to be genetically modified is placed in culture.

This is fairly accurate. Plant tissue, cells, or embryos are placed in a nutrient rich gel where they can be cultured outside of the organism. I'm told that with corn this tissue culture looks a bit like apple sauce. There are a few things I take issue with in step two (those thing will be in bold)...

2. Millions of the tissue cultured plant cells are subjected to the GM gene insertion process. This results in the GM gene(s) being insertedinto the DNA of a few of the plant cells in tissue culture. The inserted DNA is intended to re-programme the cells’ genetic blueprint, conferring completely new properties on the cell. This process would never happen in nature.It is carried out either by using a device known as a gene gun, which shoots the GM gene into the plant cells, or by linking the GM gene to a special piece of DNA present in the soil bacterium, Agrobacterium tumefaciens. When the A. tumefaciens infects a plant, the GM gene is carried into the cells and can insert into the plant cell’s DNA.

Now this process may not happen in nature due to machinery or laboratories, but I absolutely cannot let the point stand that cross-species genetic transfer never happens. This happens enough that biologist have classified and named the process. Horizontal gene transfer occurs when the genes in an offspring are not only those of it's intentional parents, but also those of parasites, symbiots, or other organisms they are in contact with. In fact the very process of using A. tumefaciens to deliver a transgene relies on a form of horizontal gene transfer.

There are also examples of horizontal gene transfer where the genomes of whole organisms have inserted themselves into another (not one gene, all the genes). These are endogenous retroviruses or ERVs, which are viruses that reverse transcribe, or write themselves into, the host's own DNA. When they do this to a germ cell, like a sperm or an egg, the genes for that virus end up in the offspring. These are actually common enough in our history that the human genome is about 5-8% fragments of ERVs.

The above examples I've given don't even cover hybridization, polyploidy, or mutation breeding, which can potentially modify far more genes and their expression characteristics than transgenic insertion. This isn't an attempt to say "It happens in nature, it must be safe!" Mercury is perfectly natural, but I'm not going to drink a glass of it. I'm merely arguing that the idea of genes of one organism being inserted into another organism is not a concept that is novel to the laboratories at Monsanto.

Conversely I can't see the point of arguing that the process never occurred in nature either. Are they trying to play the Naturalistic Fallacy?

U is unnatural. Therefore, U is wrong or bad.

Plastic tubes allowing fluid to drain from the inner ear when the Eustachian Tubes are malformed aren't readily available in the jungle, but I personally benefited from them in my lifetime. The fact that something didn't happen until we built it in a lab is not an argument against it. They immunize themselves against a claim of Argumentum Ad Naturam after the list of steps...

The fact that the GM transformation process is artificial does not automatically make it undesirable or dangerous. It is the consequences of the procedure that give cause for concern.

... but if they aren't trying to make that argument, why make it? Why point out that it is an unnatural process unless you are trying to bias an audience?

3. At this point in the process, the genetic engineers have a tissue culture consisting of hundreds of thousands to millions of plant cells. Some have picked up the GM gene(s), while others have not. The next step is to treat the culture with chemicals to eliminate all except those cells that have successfully incorporated the GM gene into their own DNA.

This is one of the more basic methods of selection, however there are newer methods that involve fluorescent detection.

4. Finally, the few cells that survive the chemical treatment are treated with plant hormones. The hormones stimulate these genetically modified plant cells to proliferate and differentiate into small GM plants that can be transferred to soil and grown on.

If the chemical bath selection method was used, this step is true.

5. Once the GM plants are growing, the genetic engineer examines them and eliminates any that do not seem to be growing well. He/she then does tests on the remaining plants to identify one or more that express the GM genes at high levels. These are selected as candidates for commercialisation[sic].

There is a glaring thing missed in this step. Sometimes the expression level you want is actually a low one. Some GMO plants currently under development, such as the Arctic Apple, are ones where genes were regulated to reduce their expression. These apples also demonstrate another drastic oversimplification of this list, they are a GMO plant, but they contain no transgenes.

6. The resulting population of GM plants all carry and express the GM genes of interest. But they have not been assessed for health and environmental safety or nutritional value. This part of the process will be discussed later in this document.

So "we haven't covered the step about health and safety screenings yet, therefore they haven't been done yet". Well, at least we have an assurance that it will be discussed later.

Conclusion

When I went out searching for a GMO proponent saying what is presented in this section, I found nothing. I found a lot of people repeating this report, but no original source for the statement. Even the geneticist I contact to get clarification on some terms and processes told me that he's never once heard a colleague use this argument. But before I called this a full on Strawman, I dug around for a source that would back up this claim. At first I found either only this paper, or people repeating the claim from this paper. After a while, someone pointed me at a paper by Jean-Pierre Zryd, from the Institute of Ecology, University of Lausanne, Switzerland. Though this was given to me as an example of a scientist in favor of GMOs saying that the process was the same as traditional breeding, I don't read him as saying the same thing.

According to some people, genetic engineering is a man made tool that goes against natural laws. In fact during this century scientists have discovered that nature does a lot of shuffling, rearranging and transferring genetic material in bacteria, plants and animals: that knowledge can now be used to speed up and improve the precision of classical genetics and traditional breeding.

As I've pointed out in this review, we actually have discovered methods by which natural processes move genes between distantly related organisms in ways that would not normally occur in standard reproduction. And the knowledge we've gained from this has allowed us to develop technology that can be used to do the same thing, but with more accuracy and with more possible benefit than blind horizontal transfer. I don't see that he's said they are the same, but merely that they can expand upon traditional breeding and the chemical rules of genetics.

This could be a matter of perspective on my part, and it could just be that it isn't the best example. My failure to Google search an example doesn't mean they aren't there, and at least one person on the side of this paper is convinced that the argument has been used. I'm willing to grant that somewhere a PR rep for Monsanto may have said something to this effect to quell a reporter's or an investor's fears. So assuming ignorance before malice without evidence of malice, I'm not going to stand behind a strawman claim here even though I'm really tempted.

Now, all that being said, what, if anything, does all this say about commercial GMOs and their risks. Would it surprise you that it says absolutely nothing?

The main premises here are.
1. GMO proponents say that the GMO process is no different from traditional plant breeding.
2. The GMO process is different.
3. ??? I'm guessing something about the paper's stated goal of exposing the risks of GMOs.

Even if I hesitate to call this a Strawman, I can in good conscience call this a full on Fallacist's Fallacy.

Argument A for the conclusion C is fallacious. Therefore, C is false.

Even if what was being said in this argument fully checks out, it means nothing to the larger question of whether the benefits of GMOs are worth the risks. By pointing out that your opponent's argument is bad, all you've done is point out that their argument is bad. In a worse case, if your opponent didn't even make that argument, what you've done is strawmanned them, defeating a ridiculous argument that they didn't hold in the first place.

And that's the first section. Thanks to Karl Haro von Mogel from BioFortified for his clarification on a few points of the genetic modification process. Also big thanks to my wife for copy editing my posts to make sure that after I've changed the direction of my argument seven times, my thoughts are still coherent on the page for others. I'll cover the insert on "Muddying Terms" in my next post before moving onto a review of their sources for section 1.2, followed by a post about section 1.2 itself.

1 comment:

Thank you for doing this. I'm a recent de-convert from the organic movement and have been doing in my own small way what you're attempting to do here. I'll be keeping in touch.

About that "gish gallop": In a manual for writing instructors that I use, there is this insightful comment about argumentation:

"What goes wrong in most essays of argument is that the arguer is writing a list of reasons for or against something. An inexperienced writer thinks that the more reasons there are, the stronger the argument will be. Just the opposite is true. An argument is one line of reasoning resting on a single base. In school debates, a speaker tries to overwhelm and confuse the opposition with mountains of "arguments," but that won't do in writing where the arguments can be examined. The base of the argument is the assumption the reasoner has to be granted to begin with. But each of the reasons on a list of reasons rests on a different base, and each asks the reader to accept a different assumption as its starting point. The more the hapless writer adds reasons, the more the argument becomes a tissue of assumptions and the more insubstantial it becomes."

From Beat Not the Poor Desk, Marie Ponsot and Rosemary Deen, Boynton,Cook.

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About Me

I am a software engineer from Atlanta. I don't believe in horoscopes, I'm a Sagittarius, we're skeptical. I also don't believe in a lot of the other things that many people tend to believe in for no good reason.

To quote Jerry DeWitt who summed this up perfectly:
"Skepticism is my nature.
Freethought is my methodology.
Agnosticism is my conclusion.
Atheism is my opinion.
Humanitarianism is my motivation."